Layered compositions with multi-charged onium ions as exchange cations, and their application to prepare monomer, oligomer, and polymer intercalates and nanocomposites prepared with the layered compositions of the intercalates

ABSTRACT

Intercalated layered materials prepared by co-intercalation of a multi-charged onium ion spacing/coupling agent and a matrix polymer between the planar layers of a swellable layered material, such as a phyllosilicate, preferably a smectite clay. The spacing of adjacent layers of the layered materials is expanded at least about 3 Å, preferably at least about 5 Å, usually to about 15-20 Å, e.g., 18 Å with the di-charged onium ion spacing/coupling agent. The intercalation of the matrix polymer then increases the spacing between adjacent layers to at least about 15 Å, preferably to about 20 Å to about 30 Å.

This application is a divisional of U.S. application Ser. No.09/272,279, filed Mar. 19, 1999 now U.S. Pat. No. 6,262,162.

FIELD OF THE INVENTION

The present invention is directed to intercalated layered materials and,optionally, exfoliates thereof, prepared by contacting, and therebyintercalating, a layered silicate material, e.g., a phyllosilicate, suchas a smectite clay, with a spacing/coupling agent that ismulti-positively charged (hereinafter “multi-charged”), preferablydual-charged, and co-intercalation of the layered material with aco-intercalant (as co-intercalant polymerizable reactants, or as theoligomer co-intercalant or polymer co-intercalant) to form nanocompositematerials. The co-intercalant monomer, oligomer or polymer can beintercalated after or together with intercalation of the multi-chargedspacing/coupling agent, such as by direct compounding, e.g., bycombining a multi-charged onium ion-intercalated layered material and aco-intercalant monomer, polymer or oligomer in a mixing or extrudingdevice to produce the co-intercalated layered material and thenanocomposite. The interlaminar spacing of adjacent layers (platelets)of the layered material (d-spacing minus one platelet thickness of thelayered material) is expanded at least 3 Å, preferably at least 5 Å, toat least about 10 Å, preferably to at least about 15 Å, and usually toabout 18 Å by contacting the layered material with the multi-chargedspacing/coupling agent for simultaneous or subsequent intercalation withco-intercalant polymer reactants, an oligomer co-intercalant or apolymer co-intercalant. The multi-charged spacing/coupling agents haveat least two charged, ion-exchange atoms capable of ion-exchanging withLi⁺, Na⁺, K⁺, Ca⁺², Mg⁺², or other inorganic cations that occur withinthe interlayer spaces between adjacent silicate layers or platelets ofthe layered silicate materials being intercalated. The association ofthe layered material inorganic cations with the at least two chargedsites of the multi-charged spacing/coupling agent enables the conversionof the hydrophilic interior clay platelet surfaces to hydrophobicplatelet surfaces, by substantially complete ion-exchange of theinterlayer exchangeable cations on the platelet surfaces with the oniumions, while intercalating and ion-exchanging substantially less oniumions into the space between adjacent platelets, leaving more space forco-intercalation of an oligomer or polymer when compared withsingle-charged onium ion analogues. Therefore, polymerizable monomerscapable of reacting to form a polymer co-intercalant, or polymerizableoligomer co-intercalant molecules, or a co-intercalant polymer can beeasily and more fully intercalated between adjacent platelets of thelayered silicate material, e.g., smectite clay platelets.

In accordance with the preferred embodiment of the present invention, afully polymerized co-intercalant polymer, having a weight averagemolecular weight between about 100 and about 5 million, preferably about1,000 to about 500,000, can be co-intercalated between adjacentplatelets of the multi-charged spacing/coupling agent-intercalatedlayered material, preferably simultaneously with dispersing themulti-charged onium ion-intercalated layered material into a matrixpolymer, i.e., by direct compounding of the multi-chargedspacing/coupling agent-intercalated layered material with theco-intercalant oligomer or polymer, by adding excess co-intercalantoligomer or polymer, and without separation of the resultingintercalate, the excess co-intercalant polymer becomes the matrixpolymer—the same as the co-intercalant polymer. The intercalation of themulti-charged spacing/coupling agent and a co-intercalant oligomer orpolymer, or its monomeric reactants (co-intercalant polymerizablemonomer reactants, co-intercalant oligomer, and co-intercalant polymerbeing referred to collectively as “intercalant polymer” or“co-intercalant polymer” hereinafter for simplicity), results in acompletely homogeneous dispersion of co-intercalated layered material ina matrix polymer, or a nanocomposite composition. Optionally, thenanocomposite material can be sheared, at or above the melt temperatureof the matrix polymer, to exfoliate up to 100% of the tactoids orplatelet clusters into individual platelets such that more than 50% byweight of the platelets are in the form of single platelets, e.g., morethan 60%; more than 70%; more than 80%; or more than 90% by weight ofthe layered material can be completely exfoliated into single plateletlayers.

The intercalates of the present invention can be used as organoclays forsorption of organic materials, or can be dispersed uniformly intosolvents to increase the viscosity of organic liquids; or theintercalates can be dispersed into matrix polymer materials to formpolymer/clay intercalate nanocomposites, e.g., by direct compounding ofthe multi-charged spacing/coupling agent-intercalated clay withsufficient co-intercalant oligomer or polymer to achieve sufficientintercalation of the clay to form a concentrate, that can later be mixedwith a matrix polymer and/or additional intercalant polymer, ordifferent polymeric materials to form a nanocomposite. Alternatively,the multi-charged spacing/coupling agent-intercalated clay can beco-intercalated with monomer reactants that are polymerizable to formthe polymer co-intercalant.

In another embodiment of the present invention, the multi-chargedspacing/coupling agent-intercalated layered material can be dispersed ina matrix monomer followed by polymerization of the matrix monomer,in-situ, e.g., by adding a curing agent, to form the nanocompositematerial. Also, curing agents can be directly incorporated intomonomeric reactants that are co-intercalated between platelets of themulti-charged spacing/coupling agent-intercalated clay followed bypolymerization of the reactant intercalant monomers that have beenintercalated into the clay interlayer galleries.

In accordance with an important feature of the present invention, if anintercalant polymer is co-intercalated into the multi-chargedspacing/coupling agent-intercalated clay galleries to form aco-intercalate and additional polymer is added to form a nanocomposite,the co-intercalant polymer can be directly compounded with the matrixpolymer to form a nanocomposite easily, and the co-intercalate can bemore fully loaded with co-intercalant polymer than if a single-chargedonium ion spacing/coupling agent were used to space the platelets. Ifthe polymerizable co-intercalant monomers, or a polymerizable oligomerintercalant is co-intercalated into the clay galleries, theco-intercalant(s) can be polymerized together with a desired monomer,oligomer or polymer matrix material, and the matrix material then can bepolymerized or further polymerized together with the co-intercalant andcompounded to form the nanocomposite.

BACKGROUND OF THE INVENTION AND PRIOR ART

It is well known that phyllosilicates, such as smectite clays, e.g.,sodium montmorillonite and calcium montmorillonite, can be treated withorganic molecules, such as organic ammonium ions, phosphonium ions, orsulfonium ions (onium ions), to intercalate the organic moleculesbetween adjacent, planar silicate layers, for ion-exchange of theorganic onium ion molecules with the interlayer exchangeable cations tospace the adjacent layers or platelets of the layered silicate material(interlaminar spacing) sufficiently for intercalation of a polymerbetween the spaced layers, see, for example, U.S. Pat. Nos. 4,739,007;4,810,734 and 5,164,460. The thus-treated, intercalated phyllosilicates,having interlayer spacings increased by at least 3 Å, preferably atleast 5 Å, to an interlayer (interlaminer) spacing of at least about10-25 Angstroms (Å) and up to about 100 Å then can be exfoliated, e.g.,the silicate layers are separated, e.g., mechanically, by high shearmixing. The individual silicate layers, when admixed with a matrixpolymer, before, after or during the polymerization of the matrixpolymer, e.g., a polyamide—see U.S. Pat. Nos. 4,739,007; 4,810,734;5,102,948; and 5,385,776—have been found to substantially improve one ormore properties of the matrix polymer, such as mechanical strength,oxygen impermeability, and/or high temperature characteristics.

Exemplary prior art composites, also called “nanocomposites”, aredisclosed in a published PCT application of Allied Signal, Inc. WO93/04118 and U.S. Pat. No. 5,385,776, disclosing the admixture ofindividual platelet particles derived from intercalated layered silicatematerials, with a matrix polymer to form a nanocomposite having one ormore properties of the matrix polymer improved by the addition of the atleast partially exfoliated intercalate. As disclosed in WO 93/04118 andU.S. Pat. No. 5,554,670, the intercalate is formed (the interlayerspacing between adjacent silicate platelets is increased) by adsorptionof a silane coupling agent or an onium cation, such as a quaternaryammonium compound, having a reactive group which is compatible with thematrix polymer. Such quaternary ammonium cations are well known toconvert a highly hydrophilic clay, such as sodium or calciummontmorillonite, into an organophilic clay capable of sorbing organicmolecules.

In accordance with a preferred embodiment of the present invention,intercalates are prepared by contacting a layered silicate material,such as a phyllosilicate, with a multi-charged onium ionspacing/coupling agent, such as a di-onium ion spacing/coupling agentcompound, and having at least 2 carbon atoms, up to about 24 carbonatoms separating the two onium cations. Exemplary of such suitablemulti-charged spacing/coupling agent molecules include quaternarydiammonium ions, disulfonium ions, diphosphonium ions, dioxonium ions,or any multi-charged onium ion compound of an element in Groups V or VIof the periodic table of elements.

The multi-charged onium ion spacing/coupling agents useful in accordancewith the present invention may be multi-charged upon dissociation ofanions from the molecule when dissolved in water and/or an organicsolvent, or the molecule may be neutral and subsequently protonated toprovide onium ion molecules having multiple positively charged atoms, insolution.

Depending upon the cation exchange capacity of the layered silicatematerial, e.g., a smectite clay, the interior platelet surfaces of thesilicate platelets include negative charge centers that have spacingsthat vary between about 4 Å and about 20 Å (equal to the spacing, ordistance, between adjacent exchangeable cations in the interlaminarspace).

In accordance with the principles of the present invention, it has beenfound that multi-charged onium ion spacing/coupling agents can beintercalated between adjacent platelets to ion-exchange with interlayercations, e.g., Na⁺ ions, to balance the negative charge centers withinthe same silicate platelet surface, at each properly spaced chargedonium ion atom, to space adjacent platelets sufficiently, using lessspacing/coupling agent. In the preferred embodiment, at least two of thecharged atoms of the multi-charged onium ion spacing/coupling agent arespaced with intermediate organic molecules, e.g., —CH₂—CH₂—;—CH₂—CH₂—CH₂; and the like, to space the charged onium ion atoms (e.g.,N^(±) space —N⁺) a distance of about 5 Å (for high charge densitylayered materials) to about 24 Å (for low charge density layeredmaterials). With such preferred spacing between charged onium ion atoms,ion-exchange with interlayer cations occurs at both charged onium ionatoms, thereby necessitating less onium ion intercalation to achievecomplete ion-exchange, while achieving sufficient silicate plateletspacing for oligomer or polymer co-intercalation, and permittingco-intercalation of higher quantities of co-intercalant oligomer orpolymer.

As shown in FIGS. 1A and 1B, a layered material having a high chargedensity, having a spacing between adjacent interlayer platelet surfacenegative charge centers in the range of about 6 Å to about 12 Å can beion-exchanged at both adjacent charged atoms of a dual-charged onium ionspacing/coupling agent that has the charged atoms spaced a distance ofabout 4 Å to about 14 Å or 16 Å. The spacing between the closest twocharged atoms of the multi-charged onium ion spacing/coupling agent neednot be exactly the same as the spacing between adjacent exchangeablecations on the platelet surface of the layered material since eachnegative charge within and extending above the platelet surface(corresponding to the location of the exchangeable cations) diffusesradially outwardly, from the negative charge center, a distance of about5 Å. The dashed line circles surrounding the adjacent negative chargecenters, as shown in FIGS. 1A and 1B, represent diffusing negativecharges that are weaker farther away from the negative charge center,and are located directly above the exchangeable cations, e.g., Na⁺, asshown in FIGS. 1A and 1B. Preferred spacing between closest chargedatoms of the spacing/coupling agent for high to medium charge density(150 milliequivelents per 100 grams C.E.C.^(*) to 70 milliequivelentsper 100 grams C.E.C.^(*)) layered materials is about 6 Å to about 20 Å,corresponding to a C₃ to C₁₀ molecule backbone in the organic spacingmolecule between charged onium ion atoms. Preferred spacing betweenonium ion spacing/coupling agent charged atoms for medium to low chargedensity (70 milliequivelents per 100 grams C.E.C.^(*) to 30milliequivelents per 100 grams C.E.C.^(*)) layered materials is about 12Å to about 24 Å, corresponding to a C6 to C₁₂ molecule backbone in theorganic spacing molecule covalently bonded to both charged onium ionatoms.

In accordance with an important feature of the present invention, bestresults are achieved by mixing the layered material with the(multi-charged spacing/coupling agent, in a concentration of at leastabout 0.25 moles of onium ion multi-positively charged, cation portionof the onium ion compound) per mole of interlayer exchangeable cations,preferably at least a 0.5:1 molar ratio, more preferably at least 1:1molar ratio of multi-charged onium ion cation:exchangeable interlayercations. When less than all of the interlayer cations are ion-exchangedwith multi-charged onium ions, the remainder of the interlayer cationscan remain in place, or at least a portion of the remaining interlayercations may be exchanged with single-charged onium ions. For mostlayered materials, such as sodium montmorillonite clays, the above molarratios are achieved by intercalating at least about 2% by weight,preferably at least about 5% by weight multi-charged spacing/couplingagent compound, more preferably at least about 10% by weight, and mostpreferably about 30% to about 200% by weight multi-chargedspacing/coupling agent cation, based on the dry weight of the layeredmaterial in the intercalating composition. Regardless of theconcentration of multi-charged spacing/coupling agent compound in theintercalating composition, the weight ratio of multi-chargedspacing/coupling agent intercalant: layered material should be at least1:20, preferably at least 1:10, more preferably at least 1:5, and mostpreferably at least about 1:4 to achieve sufficient intercalation of oneor more co-intercalants such as oligomer or polymer (or its monomericreactants) between adjacent inner surfaces of adjacent platelets of thelayered material. The multi-charged spacing/coupling agent compoundsorbed between and ion-exchanged with the silicate platelets, viaion-exchange at multiple charged atoms, causes surprisingly easyintercalation of a co-intercalant oligomer or polymer, in greateramounts than heretofore possible, or intercalation of increased amountsof monomeric reactants for polymerization in-situ.

In accordance with an important feature of the present invention, it hasbeen found that a multi-charged spacing/coupling agent-intercalatedphyllosilicate, such as a smectite clay, can be co-intercalated easilywith a co-intercalant polymer to form an intercalate that hasunexpectedly superior intercalate dispersibility in a matrix polymer,and unexpectedly can be co-intercalated with higher amounts ofco-intercalate polymer molecules. The intercalate also can be added toany other matrix polymer to enhance a number of properties of the matrixpolymer, including tensile strength, heat distortion temperature, glasstransition temperature, gas-impermeability, elongation, and the like.

The multi-charged spacing/coupling agent-intercalated layered material,that is co-intercalated with a polymer co-intercalant, and/or exfoliatesthereof, can be admixed with a matrix polymer or other organic monomercompound(s) or composition to increase the viscosity of the organiccompound or provide a matrix polymer/intercalate and/or matrixpolymer/exfoliate composition to enhance one or more of theabove-mentioned properties of the matrix polymer.

The multi-charged spacing/coupling agent-intercalated layered materialand intercalating process of the present invention provide a uniqueorganoclay useful for all known purposes of organoclays, that includesmore interlayer space for sorption of organic liquids and gases. Also,in accordance with a preferred embodiment of the present invention, theintercalate can be added, particularly by direct compounding (mixing theintercalate directly into a matrix polymer melt) of the intercalate withany matrix polymer, thermoplastic or thermosetting. Examples ofmarket-available resin systems for use as the co-intercalant polymerand/or the matrix polymer of the nanocomposites include epoxy resinssuch as: Bisphenol A-derived resins, Epoxy cresol Novolac resins, Epoxyphenol Novolac resins, Bisphenol F resins, polynuclear phenol-glycidylether-derived resins, cycloaliphatic epoxy resins, aromatic andheterocyclic glycidyl amine resins,tetraglycidylmethylenedianiline-derived resins, nylons, such as nylon-6and nylon 66, and particularly MXD6 nylon (meta-xylylene diamine andadipic acid polymerized polyamides).

DEFINITIONS

Whenever used in this Specification, the terms set forth shall have thefollowing meanings:

“Layered Material” shall mean an inorganic material, such as a smectiteclay mineral, that is in the form of a plurality of adjacent, boundlayers and has a thickness, for each layer, of about 3 Å to about 50 Å,preferably about 10 Å.

“Platelets” shall mean individual layers of the Layered Material.

“Intercalate” or “Intercalated” shall mean a Layered Material thatincludes multi-charged onium ion spacing/coupling agent moleculesdisposed between adjacent platelets of the Layered Material andion-exchanged with cations of an inner platelet surface at multiple (atleast two) charged atoms of the spacing/coupling agent to increase theinterlayer spacing between the adjacent platelets at least 3 Å,preferably at least 5 Å to an interlayer spacing, for example, of atleast about 10 Å, preferably to at least about 15 Å, e.g., 18 Å; andafter intercalation of a co-intercalant polymer, the d-spacing of theco-intercalate is increased to at least about 20 Å, preferably to 25 Åto 35 Å.

“Intercalation” shall mean a process for forming an Intercalate.

“Multi-charged Spacing/Coupling Agent” shall mean a monomeric organiccompound that includes at least two positively charged atoms, such astwo or more protonated nitrogen (ammonium or quaternary ammonium) atoms(N⁺); two or more positively charged phosphorous (phosphonium) atoms(P⁺); two or more positively charged sulfur (sulfonium) atoms (S⁺); twoor more positively charged oxygen (oxonium) atoms (O⁺); or anycombination of two or more N⁺, P⁺, S⁺ and/or O⁺ atoms that are spaced byat least two substituted or unsubstituted carbon atoms, preferablyseparated by 3 to 24, more preferably 3 to 6 carbon atoms. Preferred aredi-quaternary ammonium compounds that include two spaced positivelycharged atoms selected from N⁺, P⁺, S⁺, O⁺ or a combination of any twoor more. When dissolved in water and/or an organic solvent, an anion maydissociate from the multi-charged spacing/coupling agent compoundleaving a multi-charged cation molecule having at least two positivelycharged atoms selected from nitrogen, phosphorus, sulfur, and/or oxygen,the positively charged atoms spaced by two or more carbon atoms; themulti-charged onium ion preferably having a positively charged atomdisposed on opposite ends of a di-positively charged onium ionspacing/coupling agent intercalant molecule.

“Co-intercalation” shall mean a process for forming an intercalate byintercalation of a multi-charged spacing/coupling agent and, at the sametime or separately, co-intercalation of an oligomer or polymer, orintercalation of co-intercalant polymerizable monomers capable ofreacting or polymerizing to form a polymer.

“Concentrate” shall mean an intercalate formed by intercalation of amulti-charged spacing/coupling agent and a co-intercalant polymer, saidintercalate combined with a matrix polymer, in an intercalateconcentration greater than needed to improve one or more properties ofthe matrix polymer, so that the concentrate can be mixed with additionalmatrix polymer to form a nanocomposite composition or a commercialarticle.

“Intercalating Carrier” shall mean a carrier comprising water and/or anorganic solvent used with the multi-charged onium ion spacing/couplingagent and/or with the co-intercalant polymer or co-intercalantpolymerizable monomers or oligomers to form an Intercalating Compositioncapable of achieving Intercalation of the multi-charged onium ionspacing/coupling agent and, at the same time or separately,intercalation of the co-intercalant polymer or co-intercalantpolymerizable monomers or oligomers between platelets of the LayeredMaterial.

“Intercalating Composition” or “Intercalant Composition” shall mean acomposition comprising a multi-charged onium ion spacing/coupling agent,and/or an intercalant polymer or intercalant polymerizable monomers oroligomers and a Layered Material, with or without an IntercalatingCarrier.

“Exfoliate” or “Exfoliated” shall mean individual platelets of anIntercalated Layered Material, or tactoids or clusters of individualplatelets, e.g., 2-10 platelets, preferably 2-5 platelets, that aresmaller in total thickness than the non-exfoliated Layered Material,dispersed as individual platelets or tactoids throughout a carriermaterial, such as water, a polymer, an alcohol or glycol, or any otherorganic solvent, or throughout a matrix polymer.

“Exfoliation” shall mean a process for forming an Exfoliate from anIntercalate.

“Matrix Polymer” shall mean a thermoplastic or thermosetting polymerthat the Intercalate or Exfoliate is dispersed within to improve themechanical strength, thermal resistance, e.g., raise the glasstransition temperature (Tg), and/or the decrease gas (O₂) impermeabilityof the Matrix Polymer.

SUMMARY OF THE INVENTION

In brief, the present invention is directed to organoclays orintercalated layered materials prepared by intercalation of amulti-charged spacing/coupling agent between adjacent silicate plateletsof a swellable layered material and co-intercalates and nanocompositematerials formed by co-intercalating monomer, oligomer or polymermolecules between the spacing/coupling agent-intercalated planarsilicate layers or platelets of the swellable layered material, such asa phyllosilicate, preferably a smectite clay, such as sodiummontmorillonite clay. The spacing of adjacent layers of the layeredmaterial is expanded at least 3 Å, preferably at least about 5 Å to atleast about 10 Å, preferably to at least about 15 Å, usually about 15-30Å with the multi-charged onium ion spacing/coupling agent to form thenovel organoclays. The co-intercalation of a monomer, oligomer orpolymer (hereinafter sometimes collectively referred to as “polymer”)co-intercalant then increases the d-spacing of adjacent layers to atleast about 20 Å, preferably to about 25 Å to about 35 Å, and up toabout 300 Å, for use in increasing the viscosity of organic liquids and,in a preferred embodiment, for admixture with a matrix polymer to form ananocomposite material or composition.

The present invention is directed to a method of preparing intercalatedlayered materials prepared by intercalation of a multi-charged onium ionspacing/coupling agent and, in a preferred embodiment, co-intercalatingan oligomeric or polymeric co-intercalant into the galleries of thelayered material to form intercalates or intercalate concentratecompositions for incorporation into, as by direct compounding with amatrix polymer melt, one or more matrix polymers.

The present invention also is directed to exfoliates prepared from theintercalate or intercalate concentrate compositions. The exfoliate canbe prepared by diluting the concentrate in a (or additional) matrixpolymer, and then curing. The presence of polymerizable monomer oroligomer or polymer in the galleries of the layered materials makes thelayered materials compatible with a matrix polymer, when the intercalateis added to additional matrix polymer that is the same as the monomer,oligomer or polymer co-intercalated. When a polymer curing agent isadded, the layered materials may be exfoliated by virtue of anexpanding, polymerizing intercalated monomer or oligomer and resultingpolymer molecules dispersed between platelet layers, depending upon thedegree of polymerization achieved. The intercalates, and/or exfoliatedindividual or tactoid layers of the layered materials, will perform as apolymer reinforcement and molecule (gas) barrier in a matrix polymer toimprove the mechanical properties and barrier properties, e.g., lowergas permeability and raise glass transition temperature (Tg), of thematrix polymer. The exfoliate also can be prepared by directly adding acuring agent to the monomer-/oligomer-/or polymer-intercalatedconcentrate. The curing agent will penetrate into the gallery region ofthe intercalate to react with the polymerizable monomers, oligomers orpolymers previously co-intercalated in the interlayer gallery and formuniformly dispersed platelets or multi-layer intercalates or tactoids ina nanocomposite comprising the intercalate, and/or exfoliate thereof,and a matrix polymer.

In another embodiment of the present invention, the intercalate can beadded into a polar organic compound or a polar organiccompound-containing composition carrier or organic solvent to provideunexpectedly viscous carrier compositions, for delivery of the carrieror solvent, or for administration of an active compound that isdissolved or dispersed in the carrier or solvent. Such compositions,especially the high viscosity gels, are particularly useful for deliveryof active compounds, such as oxidizing agents for hair waving lotions,and drugs for topical administration, since extremely high viscositiesare obtainable; and for admixtures of the intercalate, or exfoliatethereof, with polar solvents in modifying rheology, e.g., of cosmetics,oil-well drilling fluids, paints, lubricants, especially food gradelubricants, in the production of lubricants, grease, and the like. Suchintercalates and/or exfoliates also are especially useful in admixturewith matrix thermoplastic or thermosetting polymers in the manufactureof nanocomposites for forming polymeric articles.

The intercalate-containing and/or exfoliate-containing organic liquidcompositions can be in the form of a stable thixotropic gel that is notsubject to phase separation and can be used to deliver any activematerials, such as in the cosmetic, hair care and pharmaceuticalindustries. The layered material is intercalated by contact with amulti-charged spacing/coupling agent to form the novel organoclays.Simultaneous or later addition of a co-intercalant oligomer or polymerto the onium ion-intercalated layered material, such as by directcompounding in an extruder to co-intercalate the oligomer or polymerbetween adjacent spaced phyllosilicate platelets and optionally separate(exfoliate) the layered material into individual platelets, provides theco-intercalated layered material for admixture with a matrix polymer toform a nanocomposite composition.

Addition of the co-intercalate to a matrix polymer melt enhances one ormore properties of the matrix polymer melt, such as strength ortemperature resistance, and particularly gas impermeability; or mixingthe intercalate or co-intercalate with a carrier or solvent materialmaintains and/or increases viscosity and thixotropy of the carriermaterial. The intercalates and co-intercalates of the present inventionare easily, homogeneously and uniformly dispersed throughout the carrieror solvent to achieve new and unexpected viscosities in thecarrier/platelet compositions even after addition of an active organiccompound, such as a cosmetic component or a medicament, foradministration of the active organic compound(s) from the composition.The co-intercalates of the present invention are easily, homogeneouslyand uniformly dispersed in a matrix polymer to provide new andunexpected gas barrier and strength properties to matrix polymers. Theabove and other aspects and advantages of the present invention willbecome more apparent from the following detailed description of thepresent invention, taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D are schematic side views of a portion of a Layered Materialplatelet showing two adjacent exchangeable Na⁺ cations on the plateletsurface and negative charge centers above the platelet surface directlyunder the Na⁺ cations, showing the negative charges diffusing radiallyoutwardly from the negative charge center, and showing di-positivelycharged onium ions, with different length spacing moieties bondedbetween the two positively charged (N⁺) atoms ion-exchanged at differentlocations with respect to the negative charge centers. FIG. 1Aschematically shows a layered material platelet having a cationic chargedensity such that negative charge centers, and the correspondingassociated cations (Na⁺) are spaced a distance L. As shown in FIGS. 1B,1C and 1D, multi-charged onium ions are able to ion exchange with theNa⁺ cations at both adjacent Na⁺ ions, while having carbon spacingmolecules R₁, R₂, and R₃ of differing lengths, due to the negativechange occupying a substantial radial distance of about 5 Å from thenegative charge center (R₁, <R₃=L<R₂). Accordingly, the distance betweenthe two positively charged atoms of the multi-charged onium ions ideallydiffer depending upon the charge density of the layered material.

FIGS. 2A and 2B are schematic representations of layered materialplatelets intercalated with single-charged (tallow amine) and discharged(tallow diamine) onium ions; and

FIGS. 3A and 3B are schematic representations of adjacent layeredmaterial platelets intercalated with single- and double-charged oniumions, as in FIGS. 2A and 2B, and co-intercalated with a polymerco-intercalant.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

To form the intercalated and exfoliated materials of the presentinvention, the layered material, e.g., the phyllosilicate, should beswelled or intercalated by sorption of a multi-charged spacing/couplingagent to form the organoclays of the present invention. To form theco-intercalated materials of the preferred nanocomposite embodiment ofthe present invention, the multi-charged onium ion-intercalated layeredmaterial is simultaneously or subsequently co-intercalated with aco-intercalant polymerizable monomer, polymerizable oligomer, orpolymer.

Useful multi-charged spacing/coupling agents include for example,tetra-, tri-, and di-onium species such as tetra-ammonium, tri-ammonium,and di-ammonium (primary, secondary, tertiary, and quaternary),-phosphonium, -oxonium, or -sulfonium derivatives of aliphatic, aromaticor arylaliphatic amines, phosphines, esters, alcohols and sulfides.Illustrative of such materials are di-onium compounds of the formula:

 R¹—X⁺—R—Y⁺

where X⁺ and Y⁺, same or different, are ammonium, sulfonium,phosphonium, or oxonium radicals such as ^(±)NH₃, ^(±)NH₂—, ^(±)N(CH₃)₃,^(±)N(CH₃)₂—, ^(±)N(CH₃)₂(CH₂CH₃), ^(±)N(CH₃)(CH₂CH₃)—, ^(±)S(CH₃)₃,^(±)S(CH₃)₂—, ^(±)P(CH₃)₃, ^(±)P(CH₃)₂—, ^(±)NH₄, ^(±)NH₃—, and thelike; R is an organic spacing, backbone radical, straight or branched,preferably having from 2 to 24, more preferably 3 to 10 carbon atoms, ina backbone organic spacing molecule covalently bonded at its ends tocharged N⁺, P⁺, S⁺ and/or O⁺ cations and R¹ can be hydrogen, or an alkylradical of 1 to 22 carbon atoms, linear or branched, preferably havingat least 6 carbon atoms. Examples of R include substituted orunsubstituted alkylene, cycloalkenylene, cycloalkylene, arylene,alkylarylene, either unsubstituted or substituted with amino,alkylamino, dialkylamino, nitro, azido, alkenyl, alkoxy, cycloalkyl,cycloalkenyl, alkanoyl, alkylthio, alkyl, aryloxy, arylalkylamino,alkylamino, arylamino, dialkylamino, diarylamino, aryl, alkylsufinyl,aryloxy, alkylsulfinyl, alkylsulfonyl, arylthio, arylsulfinyl,alkoxycarbonyl, arylsulfonyl, or alkylsilane. Examples of R¹ includenon-existent; H; alkyl having 1 to 22 carbon atoms, straight chain orbranched; cycloalkenyl; cycloalkyl; aryl; alkylaryl, eitherunsubstituted or substituted or substituted with amino, alkylamino,dialkylamino, nitro, azido, alkenyl, alkoxy, cycloalkyl, cycloalkenyl,alkanoyl, alkylthio, alkyl, aryloxy, arylalkylamino, alkylamino,arylamino, dialkylamino, diarylamino, aryl, alkylsufinyl, aryloxy,alkylsulfinyl, alkylsulfonyl, arylthio, arylsulfinyl, alkoxycarbonyl,arylsulfonyl, or alkylsilane. Illustrative of useful R groups arealkylenes, such as methylene, ethylene, octylene, nonylene,tert-butylene, neopentylene, isopropylene, sec-butylene, dodecylene andthe like; alkenylenes such as 1-propenylene, 1-butenylene,1-pentenylene, 1-hexenylene, 1-heptenylene, 1-octenylene and the like;cycloalkenylenes such as cyclohexenylene, cyclopentenylene and the like;alkanoylalkylenes such as butanoyl octadecylene, pentanoyl nonadecylene,octanoyl pentadecylene, ethanoyl undecylene, propanoyl hexadecylene andthe like; alkylaminoalkylenes, such as methylamino octadecylene,ethylamino pentadecylene, butylamino nonadecylene and the like;dialkylaminoalkylene, such as dimethylamino octadecylene,methylethylamino nonadecylene and the like; arylaminoalkylenes such asphenylamino octadecylene, p-methylphenylamino nonadecylene and the like;diarylaminoalkylenes, such as diphenylamino pentadecylene,p-nitrophenyl-p′-methylphenylamino octadecylene and the like;alkylarylaminoalkylenes, such as 2-phenyl-4-methylamino pentadecyleneand the like; alkylsulfinylenes, alkylsulfonylenes, alkylthio, arylthio,arylsulfinylenes, and arylsulfonylenes such as butylthio octadecylene,neopentylthio pentadecylene, methylsulfinyl nonadecylene, benzylsulfinylpentadecylene, phenylsulfinyl octadecylene, propylthiooctadecylene,octylthio pentadecylene, nonylsulfonyl nonadecylene, octylsulfonylhexadecylene, methylthio nonadecylene, isopropylthio octadecylene,phenylsulfonyl pentadecylene, methylsulfonyl nonadecylene, nonylthiopentadecylene, phenylthio octadecylene, ethyltio nonadecylene,benzylthio undecylene, phenethylthio pentadecylene, sec-butylthiooctadecylene, naphthylthio undecylene and the like;alkoxycarbonylalkylenes such as methoxycarbonylene, ethoxycarbonylene,butoxycarbonylene and the like; cycloalkylenes such as cyclohexylene,cyclopentylene, cyclo-octylene, cycloheptylene and the like;alkoxyalkylenes such as methoxy-methylene, ethoxymethylene,butoxymethylene, propoxyethylene, pentoxybutylene and the like;aryloxyalkylenes and aryloxyarylenes such as phenoxyphenylene,phenoxymethylene and the like; aryloryalkylenes such as phenoxydecylene,phenoxyoctylene and the like; arylalkylenes such as benzylene,phenthylene, 8-phenyloctylene, 10-phenyldecylene and the like;alkylarylenes such as 3-decylphenylene, 4-octylphenylene,4-nonylphenylene and the like; and polypropylene glycol and polyethyleneglycol substituents such as ethylene, propylene, butylene, phenylene,benzylene, tolylene, p-styrylene, p-phenylmethylene, octylene,dodecylene, octadecylene, methoxy-ethylene, moieties of the formula—C₃H₆COO—, —C₅H₁₀COO—, —C₇H₁₀COO—, —C₇H₁₄COO—, —C₉H₁₈COO—, —C₁₁H₂₂COO—,—C₁₃H₂₆COO—, —C₁₅H₃₀COO—, and —C₁₇H₃₄COO— and —C═C(CH₃)COOCH₂CH₂—, andthe like. Such tetra-, tri-, and di-ammonium, -sulfonium, -phosphonium,-oxonium; ammonium/sulfonium; ammonium/phosphonium; ammonium/oxonium;phosphonium/oxonium; sulfonium/oxonium; and sulfonium/phosphoniumradicals are well known in the art and can be derived from thecorresponding amines, phosphines, alcohols or ethers, and sulfides.

Sorption of the multi-charged spacing/coupling agent should besufficient to achieve expansion of the interlayer spacing of adjacentplatelets of the layered material (when measured dry) to at least about10 Å, preferably to at least about 15 Å, and intercalation of both themulti-charged spacing/coupling agent and co-intercalant polymer shouldachieve an interlayer spacing to at least about 20 Å, preferably to atleast about 25 Å, up to about 300 Å, usually up to about 100 Å.

The multi-charged spacing/coupling agent is introduced into the layeredmaterial galleries in the form of a solid or liquid in an intercalatingcomposition containing the layered material (neat or aqueous, with orwithout an organic solvent, e.g., an aliphatic hydrocarbon, such asheptane, to, if necessary, aid to dissolve the multi-charged onium ioncompound) having a multi-charged spacing/coupling agent concentration ofat least about 2%, preferably at least about 5% by weight multi-chargedspacing/coupling agent, more preferably at least about 50% to about 200%by weight multi-charged spacing/coupling agent in the intercalatingcomposition, based on the dry weight of the layered material, formulti-charged onium ion spacing/coupling agent sorption andion-exchange.

In the preferred embodiment, the layered material, e.g., smectite clay,is slurried in water and the multi-charged spacing/coupling agent(multi-charged cation) is dissolved in the clay slurry water, preferablyat a molar ratio of multi-charged onium ion to clay interlayer cationsof at least about 0.25:1, preferably at least about 0.5:1, morepreferably at a molar ratio of at least about 1:1. The multi-chargedspacing/coupling agent-intercalated clay then is separated from thewater easily, since the layered material, e.g., clay, is nowhydrophobic, and dried in an oven to less than 5% water, based on thedry weight of the layered material, preferably bone dry, before beingcompounded with the co-intercalant polymer and before compounding with amatrix polymer—preferably the same matrix polymer as the co-intercalantpolymer.

The multi-charged spacing/coupling agent compound can be added as asolid with the addition to the layered material/multi-chargedspacing/coupling agent compound blend of at least about 20% water,preferably at least about 30% water or more, based on the dry weight oflayered material. Preferably about 30% to about 50% water, morepreferably about 30% to about 40% water, based on the dry weight of thelayered material, is included in the multi-charged spacing/couplingagent compound intercalating composition, so that less water is sorbedby the intercalate, thereby necessitating less drying energy aftermulti-charged spacing/coupling agent compound intercalation.

The preferred multi-charged spacing/coupling agent compounds aremulti-onium ion compounds that include at least two positively chargedatoms, each (same or different) selected from primary, secondary,tertiary or quaternary ammonium, phosphonium, sulfonium, and/or oxoniumions having Formula 1, as follows:

wherein R is an alkylene, aralkylene or substituted alkylene chargedatom spacing moiety, preferably ranging from C₃ to C₂₄, more preferablyabout C₃ to C₆ for relatively high charge density (150milliequivalents/100 grams C.E.C. to 70 milliequivalents/100 gramsC.E.C.) layered materials; and preferably from C₆ to C₁₂ for medium tolow charge density (70 milliequivalents/100 grams C.E.C. to 30milliequivalents/100 grams C.E.C.) layered materials. R can be straightor branched chain, including mixtures of such moieties, i.e., C₃, C₄,C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉,C₂₀, C₂₁, C₂₂, C₂₃ and C₂₄, alone or in any combination; and R₁, R₂, R₃and R₄ are moieties, same or different, selected from the groupconsisting of hydrogen, alkyl, aralkyl, benzyl, substituted benzyl,e.g., straight or branched chain alkyl-substituted andhalogen-substituted; ethoxylated or propoxylated alkyl; ethoxylated orpropoxylated benzyl, e.g., 1-10 moles of ethoxylation or 1-10 moles ofpropoxylation. Z¹ and Z², same or different, may be non-existent, or maybe any of the moieties described for R₁, R₂, R₃ and R₄. Also, one orboth of Z¹ and Z² may include one or more positively charged atoms oronium ions.

Prior art organoclays used to intercalate clays have only been used withsingle-charged ammonium or phosphonium ions. The present inventiondiscloses the first organoclay composition which uses multi-charged,preferably double-charged cationic onium ions, to prepare organoclays.In particular, the composition of the present invention is more suitablefor polymer-clay nanocomposite preparation, such as in-reactor route anddirect compounding route. The multi-charged cationic surfactants (oniumions that have at least 1 radical bonded to one of the charged atomsthat has a length of at least C₆ up to about C₂₄) are preferred and arecommercially available at a very reasonable cost, and can providecomplete ion-exchange for the interlayer cations using much less oniumion material, leaving more room for co-intercalation of a polymer, asshown in Table I.

TABLE I Load in Chemical MW Charge Nanomer (wt %) Tallow Amine (TA) 265Mono 26.5 Tallow Diamine (TDA) 330 Dual 18.8 E185 480 Mono 40.0 EDT3 480Dual 25.0

The above dual-charged onium ion-intercalated organoclays of the presentinvention have been prepared by the di-charged onium ion-exchangereaction process. Surprisingly, both of the charged atoms of the tallowdiamine intercalant ion-exchanged on the same platelet surface of thesmectite clay and did not bridge between adjacent platelet surfaces. Toachieve the full advantage of the present invention, the distancebetween at least two of the spaced charged atoms of the multi-chargedonium ions should be in the range (within about 6 Å) of the averagedistance between two exchangeable cations or adjacent negative chargeson the clay platelet surface. For example, the average area occupied bya negative charge of a montmorillonite clay with a C.E.C. of 140milleq./100 g is in the range of 70-80 Å². Therefore, the averagedistance of the adjacent charge is in the range of 8-9 Å. The distancebetween the two charged ammonium groups in tallow diamine, wherein thetwo charged nitrogen atoms (N⁺) are spaced by three carbon atoms, isabout 8 Å.

The two charged amine groups of a tallow diamine molecule, therefore,are each disposed within about 6 Å of a negative charge center when eachreplaces an adjacent exchangeable cation (in this case, each N⁺ iswithin about 1 Å of a negative charge center) on the same silicateplatelet surface, with the tallow (R) radical extending upwardly fromthe platelet surface, as shown in FIGS. 2A, 2B, 3A and 3B.

FIGS. 3A and 3B shows the schematic difference between organoclaysprepared by using single, and double-charged onium ions. The hydrophobic(tallow) tails of the double-charged surfactants will allowintercalation of oligomer and polymer guest molecules to intercalateinto the clay galleries just like the single-charged onium ion-exchangedorganoclays. The degree of intercalation of the co-intercalant polymermolecules into the single- or double-onium ion organoclay galleries canbe assumed to be the same, based on the fact, which is the controllingfactor in intercalation, that the chain length of both intercalants isthe same. However, due to the fact that the number of long (tallow)tails of the di-charged onium ions is reduced to 50%, the volumeoccupied by the co-intercalant polymer molecules will be substantiallyincreased, as shown schematically in FIGS. 3A and 3B.

Examples of the preferred commercially available multi-charged oniumsurfactants include the following:

Tallow Diamine (TDA) Duoquad T50 (T50)

R—HN⁺—CH₂CH₂CH₂N⁺H₂;

 E-DT-3, or Ethoduomeen T13 (E-DT-3)

 DA-16/18

R—O—CH₂CH₂CH₂—HN⁺—CH₂CH₂CH₂N⁺H₂;

Tallow Triamine (T3)

R—HN⁺—CH₂CH₂CH₂N⁺H—CH₂CH₂CH₂N⁺H₂; and

Tallow Tetramine (T4)

R—HN⁺—CH₂CH₂CH₂N⁺H—CH₂CH₂CH₂N⁺H—CH₂CH₂CH₂N⁺H₂,

wherein R═C₁₄-C₁₈ alkyl chain.

The results of intercalation of monomers and polymers to themulti-charged onium ion-exchanged organoclay indicate that there is nolocking of the adjacent clay silicate layers by using multi-chargedonium ion intercalants.

Any swellable layered material that sufficiently sorbs the multi-chargedonium ion spacing/coupling agent to increase the interlayer spacingbetween adjacent phyllosilicate platelets at least 3 Å, preferably atleast 5 Å, to at least about 10 Å, preferably to at least about 15 Å canbe used in the practice of this invention. Useful swellable layeredmaterials include phyllosilicates, such as smectite clay minerals, e.g.,montmorillonite, particularly sodium montmorillonite; magnesiummontmorillonite and/or calcium montmorillonite; nontronite; beidellite;volkonskoite; hectorite; saponite; sauconite; sobockite; stevensite;svinfordite; vermiculite; and the like. Other useful layered materialsinclude micaceous minerals, such as illite and mixed layeredillite/smectite minerals, such as rectorite, tarosovite, ledikite andadmixtures of illites with the clay minerals named above.

Preferred swellable layered materials are phyllosilicates of the 2:1type having a negative charge on the layers ranging from about 0.15 toabout 0.9 charges per formula unit and a commensurate number ofexchangeable metal cations in the interlayer spaces. Most preferredlayered materials are smectite clay minerals such as montmorillonite,nontronite, beidellite, volkonskoite, hectorite, saponite, sauconite,sobockite, stevensite, and svinfordite.

As used herein the “interlayer spacing” or “interlarninar spacing”refers to the distance between the internal faces of the adjacent layersas they are assembled in the layered material before any delamination(exfoliation) takes place.

The amount of multi-charged spacing/coupling agent intercalated into theswellable layered materials, in order that the intercalated layeredmaterial platelet surfaces sufficiently ion-exchange with themulti-charged spacing/coupling agent molecules such that adjacentplatelets of the layered material may be sufficiently spaced for easyco-intercalation of a polymeric or polymerizable co-intercalant, mayvary substantially between about 2%, preferably at least about 10%, andup to about 200%, based on the dry weight of the layered material.

The multi-charged onium ion spacing/coupling agent intercalant andco-intercalant polymer may be introduced into (sorbed within) theinterlayer spaces of the layered material in a number of ways. In apreferred method of intercalating the multi-charged onium ionspacing/coupling agent between adjacent platelets of the layeredmaterial, the layered material is slurried in water, e.g., at 5-20% byweight layered material and 80-95% by weight water, and themulti-charged spacing/coupling agent compound is dissolved or dispersedin the water in which the layered material is slurried. If necessary,the multi-charged spacing/coupling agent compound can be dissolved firstin an organic solvent, e.g., propanol. The layered material then isseparated from the slurry water and dried prior to compounding with theco-intercalant polymer for intercalation of the co-intercalant and toform the nanocomposite material in a matrix polymer, preferably the samematrix polymer as the co-intercalant polymer. In a preferred method ofintercalating the co-intercalant as an oligomer or polymer, themulti-charged spacing/coupling agent-intercalated layered material isintimately mixed with the co-intercaant oligomer or polymer melt, e.g.,by extrusion or pug milling, to form an intercalating compositioncomprising the multi-charged spacing/coupling agent-intercalated layeredmaterial and co-intercalant oligomer or polymer.

The resulting multi-charged spacing/coupling agent intercalated layeredmaterial has interior platelet surfaces that are sufficientlyhydrophobic and sufficiently spaced for intercalation of theco-intercalant polymer. The multi-charged spacing/coupling agent carrier(preferably water, with or without an organic solvent) can be added byfirst solubilizing or dispersing the multi-charged spacing/couplingagent compound in the carrier; or a dry multi-charged spacing/couplingagent compound and relatively dry layered material (preferablycontaining at least about 4% by weight water) can be blended and theintercalating carrier added to the blend, or to the layered materialprior to adding the dry multi-charged spacing/coupling agent. Whenintercalating the layered material with multi-charged spacing/couplingagent in slurry form (e.g., 900 pounds water, 100 pounds layeredmaterial, 100 pounds, multi-charged spacing/coupling agent compound, theamount of water can vary substantially, e.g., from about 4% by weight,preferably from a minimum of at least about 30% by weight water, with noupper limit to the amount of water in the intercalating composition (theintercalate is easily separated from the intercalating composition dueto its hydrophobicity after multi-charged spacing/coupling agentintercalation).

Alternatively, the multi-charged spacing/coupling agent intercalatingcarrier, e.g., water, with or without an organic solvent, can be addeddirectly to the layered material, i.e., the phyllosilicate, prior toadding the multi-charged spacing/coupling agent compound, either dry orin solution. Sorption of the multi-charged spacing/coupling agentcompound molecules may be performed by exposing the layered material toa dry or liquid multi-charged spacing/coupling agent compound in themulti-charged spacing/coupling agent intercalating composition.

In accordance with another method of intercalating the multi-chargedspacing/coupling agent and co-intercalant between the platelets of thelayered material, the layered material, preferably containing at leastabout 4% by weight water, e.g., about 10% to about 15% by weight water,is blended with water and/or organic solvent solution of a multi-chargedspacing/coupling agent compound. The multi-charged spacing/couplingagent compound can be intercalated into the layered materialsimultaneously with the intercalation of a co-intercalant polymer, orthe co-intercalant polymer may be intercalated after intercalation ofthe multi-charged spacing/coupling agent. The dry multi-chargedspacing/coupling agent intercalated layered material then is extrudedwith the co-intercalant oligomer or polymer melt for direct compounding,with intercalation of the co-intercalant polymer into the multi-chargedspacing/coupling agent-intercalated layered material.

The multi-charged spacing/coupling agents have an affinity for thephyllosilicate at both, properly spaced, charged atoms to bridgeadjacent negative charge sites on a platelet surface so that themulti-charged spacing/coupling agents are sorbed onto a single plateletsurface, and are maintained bonded to the inner surfaces of the silicateplatelets, in the interlayer spaces, after exfoliation.

It is preferred that the intercalate loading be less than about 10% forpurposes of increasing the viscosity of an organic liquid carrier.Intercalate loadings within the range of about 0.05% to about 40% byweight, preferably about 0.5% to about 20%, more preferably about 1% toabout 10% significantly enhances viscosity. In general, the amount ofintercalate and/or exfoliated particles thereof incorporated into aliquid carrier, such as a polar solvent, e.g., a glycol such asglycerol, is less than about 90% by weight of the mixture, andpreferably from about 0.01% to about 80% by weight of the compositematerial mixture, more preferably from about 0.05% to about 40% byweight of the mixture, and most preferably from about 0.05% to about 20%or 0.05% to about 10% by weight.

In accordance with a preferred embodiment of the present invention, theco-intercalated layered material can be co-intercalated with anyoligomer or polymer and then dispersed into one or more melt-processiblethermoplastic and/or thermosetting matrix oligomers or polymers, ormixtures thereof, by direct compounding. Matrix polymers for use in thisembodiment of the process of this invention may vary widely, the onlyrequirement is that they are melt processible. In this embodiment of theinvention, the polymer includes at least ten (10), preferably at leastthirty (30) recurring monomeric units. The upper limit to the number ofrecurring monomeric units is not critical, provided that the melt indexof the matrix polymer is such that the matrix polymer forms a flowablemixture. Most preferably, the matrix polymer is intercalated into thedi-charged spacing/coupling agent-intercalated layered materialsimultaneously with dispersing the co-intercalated polymer uniformlyinto the matrix polymer. The matrix polymer preferably includes from atleast about 10 to about 100 recurring monomeric units, and preferably isthe same oligomer or polymer as the co-intercalant. In the mostpreferred embodiments of this invention, the number of recurring unitsis such that the matrix polymer has a melt index of from about 0.01 toabout 12 grams per 10 minutes at the processing temperature.

MXD6 nylon, obtained from Mitsubishi Gas Chemical Company, Inc., Tokyo,Japan is a polymer having the following Formula 2:

wherein n for the monomer=1;

n for the oligomer=2-10; and

n for the polymer=11-20,000,

preferably 11-1,000,

more preferably 11-500.

Other thermoplastic resins and rubbers for use as matrix monomers,oligomers or polymers in the practice of this invention may vary widely.Illustrative of useful thermoplastic resins, which may be used alone orin admixture, are polyactones such as poly(pivalolactone),poly(caprolactone) and the like; polyurethanes derived from reaction ofdiisocyanates such as 1,5-naphthalene diisocyanate; p-phenylenediisocyanate, m-phenylene diisocyanate, 2,4-toluene diisocyanate,4,4′-diphenylmethane diisocyanate, 3,3′-dimethyl-4,4′-biphenyldiisocyanate, 4,4′-diphenylisopropylidene diisocyanate,3,3′-dimethyl-4,4′-diphenyl diisocyanate,3,3′-dimethyl-4,4′-diphenylmethane diisocyanate,3,3′-dimethoxy-4,4′-biphenyl diisocyanate, dianisidine diisocyanate,toluidine diisocyanate, hexamethylene diisocyanate,4,4′-diisocyanatodiphenylnethane and the like and linear long-chaindiols such as poly(tetramethylene adipate), poly(ethylene adipate),poly(1,4-butylene adipate), poly(ethylene succinate), poly(2,3-butylenesuccinate), polyether diols and the like; polycarbonates such aspoly[methane bis(4-phenyl) carbonate], poly[1,1-ether bis(4-phenyl)carbonate], poly[diphenylmethane bis(4-phenyl)carbonate],poly[1,1-cyclohexane bis(4-phenyl)carbonate] and the like; polysulfones;polyethers; polyketones; polyamides such as poly(4-amino butyric acid),poly(hexamethylene adipamide), poly(6-aminohexanoic acid),poly(m-xylylene adipamide), poly(p-xylylene sebacamide),poly(2,2,2-trimethyl hexamethylene terephthalamide), poly(metaphenyleneisophthalamide) (NOMEX), poly(p-phenylene terephthalamide) (KEVLAR), andthe like; polyesters such as poly(ethylene azelate),poly(ethylene-1,5-naphthalate, poly(1,4-cyclohexane dimethyleneterephthalate), poly(ethylene oxybenzoate) (A-TELL), poly(para-hydroxybenzoate) (EKONOL), poly(1,4-cyclohexylidene dimethylene terephthalate)(KODEL) (cis), poly(1,4-cyclohexylidene dimethylene terephthalate)(KODEL) (trans), polyethylene terephthalate, polybutylene terephthalateand the like; poly(arylene oxides) such aspoly(2,6-dimethyl-1,4-phenylene oxide), poly(2,6-diphenyl-1,4-phenyleneoxide) and the like; poly(arylene sulfides) such as poly(phenylenesulfide) and the like;

polyetherimides; vinyl polymers and their copolymers such as polyvinylacetate, polyvinyl alcohol, polyvinyl chloride; polyvinyl butyral,polyvinylidene chloride, ethylene-vinyl acetate copolymers, and thelike; polyacrylics, polyacrylate and their copolymers such as polyethylacrylate, poly(n-butyl acrylate), polymethylmethacrylate, polyethylmethacrylate, poly(n-butyl methacrylate), poly(n-propyl methacrylate),polyacrylamide, polyacrylonitrile, polyacrylic acid, ethylene-acrylicacid copolymers, ethylene-vinyl alcohol copolymers acrylonitrilecopolymers, methyl methacrylate-styrene copolymers, ethylene-ethylacrylate copolymers, methacrylated butadiene-styrene copolymers and thelike; polyolefms such as low density poly(ethylene), poly(propylene),chlorinated low density poly(ethylene), poly(4-methyl-1-pentene),poly(ethylene), poly(styrene), and the like; ionomers;

poly(epichlorohydrins); poly(urethane) such as the polymerizationproduct of diols such as glycerin, trimethylol-propane,1,2,6-hexanetriol, sorbitol, pentaerythritol, polyether polyols,polyester polyols and the like with a polyisocyanate such as2,4-tolylene diisocyanate, 2,6tolylene diisocyante, 4,4′-diphenylmethanediisocyanate, 1,6-hexamethylene diisocyanate, 4,4′-dicyclohexyl-methanediisocyanate and the like; and polysulfones such as the reaction productof the sodium salt of 2,2-bis(4-hydroxyphenyl) propane and4,4′-dichlorodiphenyl sulfone; furan resins such as poly(furan);cellulose ester plastics such as cellulose acetate, cellulose acetatebutyrate, cellulose propionate and the like; silicones such aspoly(dimethyl siloxane), poly(dimethyl siloxane co-phenylmethylsiloxane), and the like; protein plastics; and blends of two or more ofthe foregoing.

Vulcanizable and thermoplastic rubbers useful as matrix polymers in thepractice of this embodiment of the invention may also vary widely.Illustrative of such rubbers are brominated butyl rubber, chlorinatebutyl rubber, polyurethane elastomers, fluoroelastomers, polyesterelastomers, polyvinylchloride, butadiene/acrylonitrile elastomers,silicone elastomers, poly(butadiene), poly(isobutylene),ethylene-propylene copolymers, ethylene-propylene-diene terpolymers,sulfonated ethylene-propylene-diene terpolymers, poly(chloroprene),poly(2,3-dimethylbutadiene), poly(butadiene-pentadiene),chlorosulphonated poly(ethylenes), poly(sulfide) elastomers, blockcopolymers, made up of segments of glassy or crystalline blocks such aspoly(styrene), poly(vinyl-toluene), poly(t-butyl styrene), polyestersand the like and the elastomeric blocks such as poly(butadiene),poly(isoprene), ethylene-propylene copolymers, ethylene-butylenecopolymers, polyether and the like as for example the copolymers inpoly(styrene)-poly(butadiene)-poly(styrene) block copolymer manufacturedby Shell Chemical Company under the trade name KRATON®.

Useful thermosetting resins useful as matrix polymers include, forexample, the polyamides; polyalkylamides; polyesters; polyurethanes;polycarbonates; polyepoxides; and mixtures thereof.

Most preferred thermoplastic polymers for use as a matrix polymer arethermoplastic polymers such as polyamides, particularly nylons, mostparticularly MXD6 nylon. Polyamides which may be used as matrix polymersin the process of the present invention are synthetic linearpolycarbonamides characterized by the presence of recurring carbonamidegroups as an integral part of the polymer chain which are separated fromone another by at least two carbon atoms. Polyamides of this typeinclude polymers, generally known in the art as nylons, obtained fromdiamines and dibasic acids having the recurring unit represented by thegeneral formula:

—NHCOR¹³COHNR¹⁴—

in which R¹³ is an alkylene group of at least 2 carbon atoms, preferablyfrom about 2 to about 11; or arylene having at least about 6 carbonatoms, preferably about 6 to about 17 carbon atoms; and R¹⁴ is selectedfrom R¹³ and aryl groups. Also, included are copolyamides andterpolyamides obtained by known methods, for example, by condensation ofhexamethylene diamine or metaxylylene diamine and a mixture of dibasicacids consisting of terephthalic acid and adipic acid. Polyamides of theabove description are well-known in the art and include, for example,the copolyamide of 30% hexamethylene diammonium isophthalate and 70%hexamethylene diammonium adipate, poly(hexamethylene adipamide) (nylon6,6), poly(hexamethylene sebacamide) (nylon 6, 10), poly(hexamethyleneisophthalamide), poly(hexamethylene terephthalamide),poly(heptamethylene pimelamide) (nylon 7,7), poly(octamethylenesebacamide) (nylon 8,8), poly(nonamethylene azelamide) (nylon 9,9)poly(decamethylene azelamide) (nylon 10,9), poly(decamethylenesebacamide) (nylon 10,10), poly[bis(4-aminocyclohexyl)methane-1,10-decane-carboxamide)], poly(m-xylyleneadipamide), poly(p-xylylene sebacamide), poly(2,2,2-trimethylhexamethylene terephthalamide), poly(piperazine sebacamide),poly(p-phenylene terephthalamide), poly(metaphenylene isophthalamide)and the like.

Other useful polyamides for use as a matrix polymer are those formed bypolymerization of amino acids and derivatives thereof, as, for example,lactams. Illustrative of these useful polyamides are poly(4-aminobutyricacid) (nylon 4), poly(6-aminohexanoic acid) (nylon 6),poly(7-aminoheptanoic acid) (nylon 7), poly(8-aminooctanoic acid) (nylon8), poly(9-aminononanoic acid) (nylon 9), poly(10-aminodecanoic acid)(nylon 10), poly(11-aminoundecanoic acid) (nylon 11),poly(12-aminododecanoic acid) (nylon 12) and the like.

Other matrix or host polymers which may be employed in admixture withthe di-charged spacing/coupling agent intercalant and co-intercalantpolymer of the present invention to form nanocomposites are linearpolyesters. The type of polyester is not critical and the particularpolyesters chosen for use in any particular situation will dependessentially on the physical properties and features, i.e., tensilestrength, modulus and the like, desired in the final form. Thus, amultiplicity of linear thermoplastic polyesters having wide variationsin physical properties are suitable for use in admixture with exfoliatedlayered material platelets in manufacturing nanocomposites in accordancewith this invention.

The particular polyester chosen for use as a matrix polymer can be ahomo-polyester or a copolyester, or mixtures thereof, as desired.Polyesters are normally prepared by the condensation of an organicdicarboxylic acid and an organic diol, and, the reactants can be addedto the intercalates, or exfoliated intercalates for in situpolymerization of the polyester while in contact with the layeredmaterial, before or after exfoliation of the intercalates.

Polyesters which are suitable for use as matrix polymers in thisembodiment of the invention are those which are derived from thecondensation of aromatic, cycloaliphatic, and aliphatic diols withaliphatic, aromatic and cycloaliphatic dicarboxylic acids and may becycloaliphatic, aliphatic or aromatic polyesters.

Exemplary of useful cycloaliphatic, aliphatic and aromatic polyesterswhich can be utilized as matrix polymers in the practice of thisembodiment of the invention are poly(ethylene terephthalate),poly(cyclohexylenedimethylene terephthalate), poly(ethylene dodecate),poly(butylene terephthalate), poly[ethylene(2,7-naphthalate)],poly(methaphenylene isophthalate), poly(glycolic acid), poly(ethylenesuccinate), poly(ethylene adipate), poly(ethylene sebacate),poly(decamethylene azelate), poly(decamethylene adipate),poly(decamethylene sebacate), poly(dimethylpropiolactone),poly(para-hydroxybenzoate) (EKONOL), poly(ethylene oxybenzoate)(A-tell), poly(ethylene isophthalate), poly(tetramethyleneterephthalate, poly(hexamethylene terephthalate), poly(decamethyleneterephthalate), poly(1,4-cyclohexane dimethylene terephthalate) (trans),poly(ethylene 1,5-naphthalate), poly(ethylene 2,6-naphthalate),poly(1,4-cyclohexylidene dimethylene terephthalate), (KODEL) (cis), andpoly(1,4-cyclohexylidene dimethylene terephthalate (KODEL) (trans).

Polyester compounds prepared from the condensation of a diol and anaromatic dicarboxylic acid are especially suitable as matrix polymers inaccordance with this embodiment of the present invention. Illustrativeof such useful aromatic carboxylic acids are terephthalic acid,isophthalic acid and a o-phthalic acid, 1,3-naphthalene-dicarboxylicacid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylicacid, 2,7-naphthalene-dicarboxylic acid, 4,4′-diphenyldicarboxylic acid,4,4′-diphenylsulfone-dicarboxylic acid,1,1,3-trimethyl-5-carboxy-3-(p-carboxyphenyl)-idane, diphenyl ether4,4′-dicarboxylic acid, bis-p(carboxy-phenyl) methane and the like. Ofthe aforementioned aromatic dicarboxylic acids, those based on a benzenering (such as terephthalic acid, isophthalic acid, orthophthalic acid)are preferred for use in the practice of this invention. Among thesepreferred acid precursors, terephthalic acid is particularly preferredacid precursor.

Still other useful thermoplastic homopolymers and copolymer matrixpolymers for forming nanocomposites with the co-intercalated layeredmaterials of the present invention are polymers formed by polymerizationof alpha-beta-unsaturated monomers or the formula:

R¹⁵R¹⁶C═CH₂

wherein:

R¹⁵ and R¹⁶ are the same or different and are cyano, phenyl, carboxy,alkylester, halo, alkyl, alkyl substituted with one or more chloro orfluoro, or hydrogen. Illustrative of such preferred homopolymers andcopolymers are homopolymers and copolymers of ethylene, propylene, vinylalcohol, acrylonitrile, vinylidene chloride, esters of acrylic acid,esters of methacrylic acid, chlorotrifluoroethylene, vinyl chloride andthe like. Preferred are poly(propylene), propylene copolymers,poly(ethylene) and ethylene copolymers. More preferred arepoly(ethylene) and poly(propylene).

The mixture may include various optional components which are additivescommonly employed with polar organic liquids. Such optional componentsinclude nucleating agents, fillers, plasticizers, impact modifiers,chain extenders, plasticizers, colorants, mold release lubricants,antistatic agents, pigments, fire retardants, and the like. Theseoptional components and appropriate amounts are well known to thoseskilled in the art.

The amount of intercalated layered material included in the liquidcarrier or solvent compositions to form the viscous compositionssuitable to deliver the carrier or some carrier-dissolved orcarrier-dispersed active material, such as a pharmaceutical, may varywidely depending on the intended use and desired viscosity of thecomposition. For example, relatively higher amounts of intercalates,i.e., from about 10% to about 30% by weight of the total composition,are used in forming solvent gels having extremely high viscosities,e.g., 5,000 to 5,000,000 centipoises. Extremely high viscosities,however, also can be achieved with a relatively small concentration ofintercalates and/or exfoliates thereof, e.g., 0.1% to 5% by weight, byadjusting the pH of the composition in the range of about 0-6 or about10-14 and/or by heating the composition above room temperature, e.g., inthe range of about 25° C. to about 200° C., preferably about 75° C. toabout 100° C. It is preferred that the intercalate or platelet loadingbe less than about 10% by weight of the composition. Intercalate orplatelet particle loadings within the range of about 0.01% to about 40%by weight, preferably about 0.05% to about 20%, more preferably about0.5% to about 10% of the total weight of the composition significantlyincreases the viscosity of the composition. In general, the amount ofintercalate and/or platelet particles incorporated into thecarrier/solvent is less than about 20% by weight of the totalcomposition, and preferably from about 0.05% to about 20% by weight ofthe composition, more preferably from about 0.01% to about 10% by weightof the composition, and most preferably from about 0.01% to about 5%,based on the total weight of the composition.

In accordance with an important feature of the present invention, theintercalate and/or platelet/carrier compositions of the presentinvention can be manufactured in a concentrated form, e.g., as a mastergel, e.g, having about 10-90%, preferably about 20-80% intercalateand/or exfoliated platelets of layered material and about 10-90%,preferably about 20-80% carrier/solvent. The master gel can be laterdiluted and mixed with additional carrier or solvent to reduce theviscosity of the composition to a desired level.

In one embodiment, the intercalates, and/or exfoliates thereof, aremixed with a carrier or solvent to produce viscous compositions of thecarrier or solvent optionally including one or more active compounds,such as an antiperspirant compound, dissolved or dispersed in thecarrier or solvent.

When shear is employed for exfoliation, any method which can be used toapply a shear to the intercalate/matrix polymer nanocompositecomposition can be used. The shearing action can be provided by anyappropriate method, as for example by mechanical means, by thermalshock, by pressure alteration, or by ultrasonics, all known in the art.In particularly useful procedures, the composition is sheared bymechanical methods in which the intercalate, with or without the carrieror solvent, is sheared by use of mechanical means, such as stirrers,Banbury® type mixers, Brabender® type mixers, long continuous mixers,and extruders. Another procedure employs thermal shock in which shearingis achieved by alternatively raising or lowering the temperature of thecomposition causing thermal expansions and resulting in internalstresses which cause the shear. In still other procedures, shear isachieved by sudden pressure changes in pressure alteration methods; byultrasonic techniques in which cavitation or resonant vibrations whichcause portions of the composition to vibrate or to be excited atdifferent phases and thus subjected to shear. These methods of shearingare merely representative of useful methods, and any method known in theart for shearing intercalates may be used.

Mechanical shearing methods may be employed such as by extrusion,injection molding machines, Banbury® type mixers, Brabender® type mixersand the like. Shearing also can be achieved by introducing the layeredmaterial and intercalant monomer at one end of an extruder (single ordouble screw) and receiving the sheared material at the other end of theextruder. The temperature of the layered material/intercalant monomercomposition, the length of the extruder, residence time of thecomposition in the extruder and the design of the extruder (singlescrew, twin screw, number of flights per unit length, channel depth,flight clearance, mixing zone, etc.) are several variables which controlthe amount of shear to be applied for exfoliation.

In accordance with an important feature of the present invention, it hasbeen found that the multi-charged spacing/coupling agent-intercalatedclay can be co-intercalated with an oligomer or polymer by directcompounding, i.e., by mixing the multi-charged onium ion-intercalatedclay directly with the co-intercalant oligomer or polymer in an extruderto make the co-intercalated clay without significant exfoliation of theclay platelets. The co-intercalate-filled matrix polymer extrudes into ahomogeneous transparent film with excellent dispersion of theco-intercalate, and/or exfoliate thereof. The co-intercalate, and/orexfoliate thereof, dispersed within the matrix polymer may bepredominantly in the form of multi-layer tactoids dispersed in thematrix polymer. The tactoids have the thickness of at least twoindividual platelet layers plus the ion-exchanged di-charged intercalantspacing/coupling agent and one to five monolayer thicknesses of theco-intercalant polymer, and include small multiples or aggregates ofless than about 10 platelets, in a coplanar aggregate, preferably lessthan about 5, more preferably less than about 3 platelet layers, stillmore preferably 2 or 3 platelet layers having the multi-chargedspacing/coupling agent compound and co-intercalant polymer betweenplatelet surface(s). The nanocomposite compositions, including thematrix polymer, can include the layered material as all intercalates,completely without exfoliation, while maintaining transparency,excellent intercalate dispersibility, and excellent gas impermeability.

Molding compositions comprising a matrix polymer containing a desiredloading of the co-intercalates of the present invention, and/orindividual platelets obtained from exfoliation of the co-intercalatesmanufactured according to the present invention, are outstandinglysuitable for the production of sheets, films and panels having valuableproperties. Such sheets, films and panels may be shaped by conventionalprocesses such as vacuum processing or by hot pressing to form usefulobjects. The sheets and panels according to the invention are alsosuitable as coating materials for other materials comprising, forexample, wood, glass, ceramic, metal or other plastics, and outstandingstrengths can be achieved using conventional adhesion promoters, forexample, those based on vinyl resins. Beverage containers, e.g., plasticbeer/wine bottles having new and unexpected shelf life are possibleusing matrix polymers filled with, e.g., 1-10% by weight of theco-intercalates of the present invention, either as a sole layer, orsecured to or between one or more other layers, as known in the art. Thesheets, films and panels can be laminated to other plastic films, sheetsor panels and this is preferably effected by co-extrusion, the sheetsbeing bonded in the molten state. The surfaces of the sheets, films andpanels, including those in the embossed form, can be improved orfinished by conventional methods, for example by lacquering or by theapplication of protective films.

Matrix polymer/intercalate composite materials are especially useful forfabrication of extruded films and film laminates, as for example, filmsfor use in food packaging that have low O₂ permeabilities. Such filmscan be fabricated using conventional film extrusion techniques. Thefilms are preferably from about 10 to about 100 microns, more preferablyfrom about 20 to about 100 microns and most preferably from about 25 toabout 75 microns in thickness.

The homogeneously distributed intercalate, and/or exfoliated plateletsthereof, which has been co-intercalated in accordance with the presentinvention, and a matrix polymer can be formed into a film by suitablefilm-forming methods. Typically, the composition is melted and forcedthrough a film forming die after oligomer or polymer co-intercalationand compounding. The film of the nanocomposite may go through sequentialsteps to cause the intercalate and/or exfoliated platelets thereof to befurther oriented so the major planes through the co-intercalates and/orplatelets thereof are substantially parallel to the major plane throughthe film. One method to accomplish this is to biaxially stretch thefilm. For example, the film is stretched in the axial or machinedirection by tension rollers pulling the film as it is extruded from thedie. The film is simultaneously stretched in the transverse direction byclamping the edges of the film and drawing them apart. Alternatively,the film is stretched in the transverse direction by using a tubularfilm die and blowing the film up as it passes from the tubular film die.The films may exhibit one or more of the following benefits in additionto decreased permeability to gases, particularly O₂: increased modulus;increased wet strength; increased dimensional stability; and decreasedmoisture adsorption.

The following examples are presented to more particularly illustrate theinvention and are not to be construed as limiting the scope of theinvention.

EXAMPLE 1

This example demonstrates the formation of a double-charged oniumion-modified (organophilic) montmorillonite clay. The onium ion is aneutral amine (primary and secondary) and can be protonated by contactwith HCl.

One hundred grams of Na-montmorillonite clay (PGW) commerciallyavailable from Nanocor, Inc. (Arlington Heights, Ill.) was dispersed in3 liters of de-ionized water by mechanical paddle mixer or colloidalmill. The clay dispersion was heated to 75° C. to 80° C. 26.4 g ofTallow di-amine, available from Tomah Products, was mixed with 70 ml, 2N HCl in 1 liter of 75° C. to 80° C. de-ionized water. The amine-HClsolution was introduced to the clay dispersion, followed by vigorousmixing. The mixture was maintained at 75° C. to 80° C. for about 30min., followed by a de-watering process, such as filtration. The filtercake was re-dispersed into 4 liters of 75° C. to 80° C. water and thesolid (filter cake) was collected and placed into a 75° C. to 80° C.oven to dry followed by particle size reduction. The filter cake alsocan be freeze-dried. The dried material has a d001 spacing of 17 Å asmeasured by X-ray diffraction and was coded as TDA-2H-PGW. Tallow aminealso can be used to prepare treated montmorillonite with essentially thesame procedure, but with a higher amount of Tallow amine, e.g., 37.1grams. The product is coded as TA-PGW, with a d001 spacing of 22 Å.

EXAMPLE 2

This example demonstrates the formation of a double-charged onium-ionmodified (organophilic) montmorillonite clay. The onium ion is a neutralamine (tertiary) and can be protonated with contact with HCl.

One hundred grams of Na-montmorillonite clay (PGW) commerciallyavailable from Nanocor, Inc. (Arlington Heights, Ill.) was dispersed in3 liters of de-ionized water by mechanical paddle mixer or colloidalmill. The clay dispersion was heated to 75° C. to 80° C. 33.6 g ofE-DT-3 amine, available from Tomah Products, was mixed with 70 ml, 2 NHCl in 1 liter of 75° C. to 80° C. de-ionized water. The amine-HClsolution was introduced to the clay dispersion, followed by vigorousmixing. The mixture was maintained at 75° C. to 80° C. for about 30min., followed by a de-watering process, such as filtration. The filtercake was re-dispersed into 4 liters of 75° C. to 80° C. water and thesolid (filter cake) was collected and placed into a 75° C. to 80° C.oven to dry followed by particle size reduction. The filter cake alsocan be freeze-dried. The dried material has a d001 spacing of 17 Å asmeasured by X-ray diffraction and was coded as E-TD-3-2H-PGW.

EXAMPLE 3

This example demonstrates the formation of a double-charged oniumion-modified (organophilic) montmorillonite clay. The onium ion is adouble-charged quaternary ammonium cation.

One hundred grams of Na-montmorillonite clay (PGW) commerciallyavailable from Nanocor, Inc. (Arlington Heights, Ill.) was dispersed in3 liters of de-ionized water by mechanical paddle mixer or colloidalmill. The clay dispersion was heated to 75° C. to 80° C. 67.2 g ofDuoquadT50 (50% solid), available from Akzo Nobel, was mixed with 1liter of 75° C. to 80° C. de-ionized water. The T50 solution wasintroduced to the clay dispersion followed by vigorous mixing. Themixture was maintained at 75° C. to 80° C. for about 30 min., followedby a de-watering process, such as filtration. The filter cake wasre-dispersed into 4 liters of 75° C. to 80° C. water and the solid wascollected and placed into a 75° C. to 80° C. oven to dry followed byparticle size reduction. The filter cake also can be freeze-dried. Thedried material has a d001 spacing of 19 Å as measured by X-raydiffraction and was coded as T50-PGW.

EXAMPLES 4-6

These examples illustrate the formation of clay intercalates bycombining the multi-charged onium ion-modified (organophilic) clays withnon-polymeric organic compounds.

5 grams of the products of Examples 1-3, TDA-2H-PGW, TA-PGW,E-DT-3-2H-PGW, and T50-PGW were mixed with 45 grams of the followingnon-polymeric organic compounds, ε-caprolactam at 70° C. to 90° C.,DGEBA DER331 at 70° C. to 80° C. and Resorcinol bis- (diphenylphosphate) (RDP, Akzo Nobel) at 70° C. to 80° C. The mixtures werecooled to room temperature and placed on a microscopic glass slide tomeasure X-ray diffraction patterns. The results are given in theTable 1. The intercalates of the multi-charged onium ion-treated claywith the non-polymeric organic compounds also can be formed by mixingthe non-polymeric organic compounds with the filter cake followed byde-watering, drying and particle size reduction. The d001 results arenearly identical to the results generated from dispersion route ofExamples 1-3. The results in Table 1 indicate successful intercalationof non-polymeric organic compounds into the interlayer spacing of themulti-charged onium ion-treated clays. The multi-charged oniumion-treated clays perform similarly to the normal organoclays. The longaliphatic tails (C₆+) of the preferred multi-charged onium ions provideexceptional degrees of intercalation.

TABLE 1 d₀₀₁ results of the multi-charged onium ion-modified claysdispersed in non-polymeric organic compounds by X-ray diffraction. d₀₀₁d₀₀₁ (Å) d₀₀₁ (Å) d₀₀₁ (Å) (Å) in capro- in in Examples Clays claylactam DER 331 RDP 4 TDA-2H-PGW 16 33 34 34 4 TA-PGW 22 32 36 33 5E-DT-3-2H-PGW 18 33 38 35 6 T50-PGW 19 32 36 34 Comparative PGW 13 13 1313 1

COMPARATIVE EXAMPLE 1

For comparison, 5 grams of the untreated Na-montmorillonite clay (PGW)was mixed with the above-mentioned non-polymeric organic compounds, andits mixtures were examined by X-ray diffraction. The result is includedin Table 1. No intercalation of the organic molecules was observed.

EXAMPLES 7-9

These examples illustrate the formation of a polymer-clay nanocompositeby melt compounding.

Melt compounding was used to prepare polymer clay nanocomposites.Thermoplastic resins, Nylon6 (PA6), Poly methyl methacrylate (PMMA) andNylon MXD6 (MXD6) were selected as the matrices. Resin pellets andmulti-charged onium ion-intercalated clay were fed into a twin screwextruder (Leistritz Micro27) at elevated temperatures (above the meltingpoints of the resins), e.g., for PMMA the temperatures of the extruderzones were in the range of 210° C. to 230° C. The ratio of themulti-charged onium ion-intercalated clays to the resins were controlledat 5:95 by weight. The compounded composite strings from the extruderwere cooled in a cold water bath prior to being pelletized. Thenanocomposite of PA6, and MXD6 were cast to 2 mil-thick filns and OTR(Oxygen Transmittance Rate) results were measured at 65% RH at 23° C. byusing a Mocon OX-Tran2/20. PMMA-clay nanocomposites were molded intoASTM standard testing specimens to test HDT (Heat DeflectionTemperature). The dispersion results of the multi-charged oniumion-treated clays in the above-mentioned resins are listed in Table 2.X-ray diffraction patterns were obtained from the PA6-clay, MXD6-clayfilm nanocomposites and PMMA-clay nanocomposite bar. The X-raydiffraction results are shown in Table 3.

TABLE 2 The observation of the clay dispersion of the multi-chargedonium ion-treated clays and Na-montmorillonite clay (PGW) in Nylon6(PA6), Poly (methyl methacrylate) (PMMA) and Nylon MXD6 (MXD6). ExamplesClays PA6 PMMA MXD6 7 TDA-2H-PGW excellent excellent excellent 8E-DT-3-2H-PGW very good excellent excellent 9 T50-PGW very good verygood excellent Comparative PGW poor poor poor 2 Excellent: The extrudedpellets and cast films are almost transparent and no particles wereobserved by optical microscope at ×100. Very good: The extruded pelletsand cast films are slightly opaque and no particles were observed byoptical microscope at ×100. Good: The extruded pellets and cast filmsare opaque and gel-body like particles were observed by opticalmicroscope at ×100. Poor: The pellets have visible particles, and arehazy. The film cast from the pellets have a visible discontinues phaseand voids.

The melted resin polymers are intercalated into the multi-charged oniumion-treated clays to form resin-clay nanocomposites in the extrusionprocess. The X-ray diffraction results indicate that the original claylayer stacking has been interrupted by the resin intercalation. The OTRresults of the PA6, and MXD6 nanocomposites have more than 30% reductioncompared with the unfilled resins, respectively. The HDT of the PMMAnanocomposite increases nearly 10° C. over the pure PMMA resin.

TABLE 3 d₀₀₁ results of nanocomposite containing the multi-charged oniumion-treated clays dispersed in thermoplastic resins through meltcompounding by X-ray diffraction. d₀₀₁ (Å) d₀₀₁ (Å) d₀₀₁ (Å) d₀₀₁ (Å) inExamples Clays clay in PA6 in PMMA MXD6 7 TDA-2H-PGW 16 >31 32 >33 8E-DT-3-2H-PGW 18 >30 33 >32 9 T50-PGW 19 >34 34 >33 Comparative PGW 1311 12 11 2

COMPARATIVE EXAMPLE 2

For comparison, 5 wt % of the untreated Na-montmorillonite clay (PGW)was compounded with Nylon6 (PA6), Poly (methyl methacrylate) (PMMA) andNylon MXD6 (MXD6) using the same conditions as for the multi-chargedonium ion-treated clays. The resins filled with untreated PGW have verypoor dispersion (Table 2). The cast films have visible voids, and themolded sample bars have rough surfaces and clay aggregates. The X-raydiffraction results (Table 3) indicate no intercalation of polymerresins into the clay interlayer spacing. Also, the dehydration (drying)of the clay collapsed the clay galleries in the heated extrusionprocess.

EXAMPLE 10

This example illustrates the formation of a Nylon6-TDA-2H-PGWnanocomposite through a caprolactam polymerization route.

70 g of TDA-2H-PGW was mixed with 2,000 grams of caprolactam at 80° C.overnight, prior to being placed into a reactor. The reactor is equippedwith constant speed pedal mixer and purged with nitrogen. The reactiontime is 12 hr. at 260° C. The reaction product was broken into smallpieces with liquid nitrogen cooling and washed in boiling water toremove residual caprolactam. A 2 mil-thick film was cast and OTR wasmeasured on the Mocon OX-Tran 2/20. The nanocomposite containing TA-PGWwas prepared by the same method. The comparison of OTR results of theunfilled resin and nanocomposites is shown in Table 4.

TABLE 4 Comparison of OTR of Nylon6-clay nanocomposites prepared withtraditional onium ion-treated clay (TA-PGW) and the multi-charged oniumion-treated clay (TDA-2H-PGW). OTR Sample Name Clay, wt % (cc-mil/100in²/day) % change Control 0.0 3.24 100% TA-PGW 2.0 2.11 −35% TDA-2H-PGW2.4 1.40 −57%

The nanocomposite prepared from the multi-charged onium ion-treated clayhas significantly reduced oxygen permeability compared with thetraditional (single charged onium ion) treated clay. Also, othermechanical, thermal and solvent resistance properties are better thanthose of the nanocomposites prepared from the traditional single chargedonium ion-treated clays.

What is claimed is:
 1. In a method of preventing the passage of oxygento a material to be protected from oxygen contact comprising disposing afilm of sheet material between an oxygen source and the material to beprotected, the improvement comprising the film of sheet material, saidfilm of sheet material comprising a matrix polymer having homogeneouslydispersed therein a surface-modified smectite clay having amulti-charged onium ion intercalated and ion-exchanged in place ofmultiple interlayer cations in an amount sufficient to reduce the amountof oxygen contacting the material to be protected.
 2. In the method ofclaim 1, wherein the surface-modified smectite clay is dispersedthroughout the matrix polymer in an amount of about 2% to about 10% byweight of the matrix polymer.
 3. In the method of claim 1, wherein thematrix polymer is selected from the group consisting of an epoxy, apolyamide, and polyethylene terephthalate.
 4. The method of claim 1,wherein the surface-modified smectite clay comprises stacked layers ofsmectite clay silicate platelets having, at the platelet internalsurfaces, a multi-charged onium ion selected from the group consistingof di-ammonium, di-phosphonium, di-sulfonium, di-oxonium;ammonium/phosphonium; ammonium/sulfonium; ammonium/-oxonium;phosphonium/sulfonium; phosphonium/oxonium; sulfonium/oxonium; andmixtures thereof, intercalated and ion-exchanged in place of multipleinterlayer cations.
 5. The method of claim 1, wherein the interlayercations are substituted with multi-charged onium ions in a molar ratioof at least 0.25 moles of multi-charged onium ions per mole ofinterlayer exchangeable cations, to expand the interlayer spacing of theclay silicate platelets at least about 3 Å.
 6. The method of claim 5,wherein the molar ratio of multi-charged onium ions to clay interlayerexchangeable cations is at least 0.5:1.
 7. The method of claim 6,wherein the molar ratio of multi-charged onium ions to clay interlayerexchangeable cations is at least 1:1.
 8. The method of claim 1, whereinthe multi-charged onium ions are selected from the group consisting ofdi-ammonium, di-sulfonium, di-oxonium; ammonium/-phosphonium;ammonium/sulfonium; ammonium/oxonium; phosphonium/sulfonium;phosphonium/oxonium; sulfonium/oxonium; and mixtures thereof.
 9. Themethod of claim 1, wherein the ion-exchange is achieved by dispersingthe smectite clay and the multi-charged onium ions in a carriercomprising water to contact the smectite clay with the multi-chargedonum ions for a time sufficient to ion-exchange the multi-charged oniumions for at least a portion of the smectite clay interlayer cations;separating the ion-exchanged smectite clay from the carrier; drying theion-exchanged smectite clay; and grinding the smectite clay to a desiredparticle size distribution.
 10. The method of claim 1, wherein the oniumion includes two positively charged atoms separated by 5 Å to 24 Å. 11.The method of claim 10, wherein the onium ion includes an organicradical covalently bonded to one of the positively charged atoms havinga chain length of at least 6 carbon atoms.
 12. The method of claim 10,wherein the 5 Å to 24 Å spacing between positively charged atoms isachieved by a separating moiety having 3 to about 12 carbon atoms in itsbackbone.
 13. The method of claim 1, wherein the multi-charged onium ionis a compound of the formula:

wherein R is an alkylene, aralkylene or substituted alkylene spacingmoiety, ranging from C₃ to C₂₄, straight or branched chain, R₁, R₂, R₃and R₄ are moieties, same or different, selected from the groupconsisting of hydrogen, alkyl, aralkyl, benzyl, substituted benzyl,straight or branched chain alkyl-substituted and halogen-substituted;ethoxylated alkyl; propoxylated alkyl; ethoxylated benzyl; propoxylatedbenzyl; Z¹ and Z², same or different, are selected from the groupconsisting of non-existent and any of the moieties as defined for R₁,R₂, R₃ and R₄.
 14. The method of claim 13, wherein Z¹ or Z² ispositively charged.
 15. The method of claim 1, wherein the matrixpolymer is a polyamide oligomer or polymer.
 16. The method of claim 1,wherein the onium ion includes an organic radical covalently bonded toone of the positively charged atoms, said organic radical having a chainlength of at least six carbon atoms.
 17. The method of claim 1, whereinsaid film comprises about 0.05 weight percent to about 40 weight percentof said surface-modified smectite clay and about 60 weight percent toabout 99.95 weight percent of said matrix polymer, wherein theintercalated smectite clay is dispersed uniformly throughout the matrixpolymer.
 18. The method of claim 17, wherein the matrix polymer isco-intercalated into the surface-modified smectite clay.
 19. The methodof claim 18, wherein the matrix polymer is co-intercalated into thesmectite clay while dispersing the layered material throughout thematrix polymer.
 20. The method of claim 18, wherein the matrix polymeris co-intercalated into the smectite clay prior to dispersing thesmectite clay throughout the matrix polymer.
 21. The method of claim 11,wherein the matrix polymer is a polymer or oligomer of the reactionproduct of meta-xylylene diamine and adipic acid.
 22. The method ofclaim 11, wherein the multi-charged onium ions include at least onemoiety covalently bonded to a protonated nitrogen atom that has a lengthof at least six carbon atoms.
 23. The method of claim 1, wherein thefilm comprises a matrix polymer in an amount of about 40% to about99.95% by weight, and about 0.05% to about 60% by weight of saidintercalated smectite clay formed by contacting a smectite clay withsaid intercalant multi-charged onium ions to form an intercalatingcomposition, having a molar ratio of multi-charged onium ions:smectiteclay interlayer exchangeable cations of at least about 0.25:1 to achievesorption of the multi-charged onium ions between adjacent spaced layersof the smectite clay to expand the spacing between a predominance of theadjacent smectite clay platelets at least about 3 Å, when measured aftersorption of the multi-charged onium ions, and a second intercalantdisposed between adjacent spaced layers of the smectite clay material,said second intercalant comprising a thermosetting or thermoplasticoligomer or polymer.
 24. The method of claim 23, wherein theintercalated smectite clay is exfoliated into a predominance ofindividual platelets.
 25. The method of claim 1, wherein the matrixpolymer is selected from the group consisting of an epoxy; a polyamide;a polyvinyl alcohol; a polycarbonate; a polyvinylimine; apolyvinylpyrrolidone; a polyethylene terephthalate; and a polybutyleneterephthalate.
 26. The method of claim 1, wherein the matrix polymer isa polymer of meta-xylylene diamine and a dicarboxylic acid.
 27. Themethod of claim 21, wherein the matrix polymer is intercalated into thesmectite clay.
 28. The method of claim 26, wherein prior tointercalating the smectite clay with the polymer of meta-xylylenediamine and a dicarboxylic acid, the smectite clay is first intercalatedwith multi-charged onium ions that include at least one moietycovalently bonded to a positively charged nitrogen atom that has alength of at least six carbon atoms.
 29. The method of claim 1, whreinthe film is manufactured by contacting said smectite clay withmulti-charged onium ions to intercalate the multi-charged onium ionsbetween adjacent layers of the smectite clay, thereby increasing thespacing between adjacent layers of the smectite clay at least 3 Å, andsimultaneously or subsequently contacting the smectite clay with anoligomer or polymer in a form selected from the group consisting of (i)a solution of the oligomer or polymer, (ii) a dispersion of saidoligomer or polymer and (iii) a melt of said oligomer or polymer, tointercalate said oligomer or polymer between adjacent layers of saidsmectite clay and thereby further expand the spacing between adjacentlayers of said smectite clay an additional at least 3 Å.
 30. A method ofclaim 29, wherein the matrix oligomer or polymer is intercalated intothe smectite clay by melting the matrix oligomer or polymer anddispersing the intercalated smectite clay throughout the melt.
 31. Amethod of claim 30, wherein the mixing is accomplished in an extruder.